Collaborative Research: SHF: Medium: Responsive Parallelism for Interactive Applications: Theory and Practice

近年来硬件的进步使多核芯片和并行计算成为主流。因此，在过去的几十年里，并行计算的研究和发展一直主导着传统的科学应用。我们现在必须考虑交互式应用程序中的并行性，这种应用程序的特点是与用户或其他软件系统进行频繁的交互，因此必须具有响应性。这个项目的目的是开发一种交互式并行应用程序的实用方法。这个项目的新颖之处在于，除了关注并行性和交互的交叉点之外，它还遵循了一种端到端的方法，将计算机科学的许多领域结合在一起，并将理论与实践联系起来。该项目有可能影响需要大规模交互应用程序的几个应用程序领域的设计，包括web服务、CAD/CAM桌面客户端、游戏和各种移动应用程序。这项研究的端到端目标需要在类型系统、编程语言、调度理论和运行时系统方面取得进展。该研究小组将开发一种演算，用于在高抽象层次上对交互式并行应用程序进行建模。这种演算将为基于Church λ演算的完全通用的形式编程语言提供成本语义，使其能够1)表达交互式并行应用程序，2)对程序的吞吐量和响应性进行推理。类型系统将确保没有棘手的错误，如优先级反转，这会妨碍建立响应性保证。研究人员将通过开发能够忠实匹配成本语义的调度算法来证明这种演算是可以实现的，从而保证期望的性能标准。在实践方面，项目团队将扩展Cilk（一种基于c语言的并行编程语言），以支持交互式并行应用程序。这将需要开发一个运行时系统，它忠实地实现调度算法和优化，以确保实际性能。这个项目的教育部分，包括教授本科生并行算法，将创造充足的机会来测试所提出方法的实际有效性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The hardware advances of recent years have brought multicore chips and parallel computing to the mainstream. As a result, today, parallelism is not found just in the traditional scientific applications that have dominated research and development in parallel computing in past decades. We must now consider parallelism in interactive applications which are characterized by frequent interactions with users or other software systems and therefore must be responsive. This project’s aim is to develop a practical approach to interactive parallel applications. The project’s novelty, in addition to focusing on this under-studied intersection of parallelism and interaction, is that it follows an end-to-end methodology that brings together many areas of computer science and bridges theory with practice. The project has the potential to impact the design of several application areas that require large-scale interactive applications, including web services, desktop clients for CAD/CAM, games, and a variety of mobile applications. This research’s end-to-end goals require advances in type systems, programming languages, scheduling theory, and runtime systems. The research team will develop a calculus for modeling interactive parallel applications at a high level of abstraction. This calculus will equip a fully general formal programming language based on Church's Lambda Calculus with a cost semantics, making it possible 1) to express interactive parallel applications and 2) to reason about the throughput and responsiveness of the programs. A type system will ensure the absence of thorny bugs such as priority inversions that can prevent establishing responsiveness guarantees. The investigators will prove that this calculus is realizable by developing scheduling algorithms that can faithfully match the cost semantics so as to guarantee the desired performance criteria. On the practical side, the project team will extend Cilk, a C-based parallel programming language, to support interactive parallel applications. This will require developing a run-time system that faithfully implements the scheduling algorithms and optimizations that ensure practical performance. The educational component of this project, which involves teaching undergraduates parallel algorithms, will create ample opportunities to test the practical effectiveness of the proposed approach.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.